Barry and Iris are attending the activation of the particle accelerator when someone steals Iris's bag in pilot episode. Hartley Rathaway shows Cisco some evidence of the fate of Ronnie in episode 1x12 "Crazy for You". From episode 1x13 "The Nuclear Man". Appears in 2 more episodes.
The DeVoes steal a rare alloy and Clifford kills a guard despite Marlize's objections in episode 4x20 "Therefore She Is".
The team heads to stop DeVoe from aquiring the quantum computer he needs to coordinate his devices but their attempt is thwarted by Marlize in episode 4x20 "Therefore She Is".
Eobard Thawne, posing as a NASA medical officer, talks to an astronaut who is set to travel on Apollo 13 in episode 2x13 "Land of the Lost". The Legends infiltrate the NASA complex and track down Henry Heywood. Stein and Rory end up watching the events of Apollo 13 from mission control in episode 2x14 "Moonshot".
Kara and Mon-el head to the police parking garage where a group of officers is under attack by what appears to be Livewire in episode 2x10 "We Can Be Heroes".
Kara yells at Mon-El outside the DEO after he disobeyed her orders and put the police officers at risk in episode 2x10 "We Can Be Heroes".